The present invention relates to an apparatus for changing the workpieces and tool automatically in a gear cutting machine.
Hobbing type gear cutters generally comprise a head capable of both vertical and horizontal movement, to which the hob is mounted. The head is composed of a spindle and a support or bearing, horizontally and coaxially disposed, between and by which the hob is supported and set in motion. The spindle and the bearing are capable of movement independently, toward and away from one another such that the tool can be clamped and released, respectively.
The entire head is capable of horizontal movement toward a station equipped with means by which the blanks for cutting are supported and set in motion. In most instances, the machine is equipped with an apparatus consisting in a vertical post rotatable about its own axis, by which each successive piece cut is replaced with a fresh blank automatically. Such apparatus affords a plurality of peripherally disposed restraining and/or supporting elements by which the blanks are picked up from a feeder and transferred to and from the machining station. Tool change on the other hand is generally a manual operation, not least by reason of the fact that the cutter is changed less frequently than the work. It happens nonetheless that machines capable of cutting significantly large blanks utilize tools of some considerable weight, the handling of which is laborious for a machine operator, and hazardous too in the case of a hob due to the particular geometry and sharpness of the cutting edges. The replacement of the tool is rendered still more difficult by the small amount of room existing between the tool head on the one hand, and the blank, or the restraining and/or support elements associated with the post which carry the blank, on the other.
Accordingly, the object of the present invention is to provide a simple apparatus for association with gear cutting machines, by which cutting tools can be changed automatically.